The present invention relates to an occupant safety restraint seat belt system and more particularly to an improvement in a D-ring for supporting a portion of a safety or seat belt webbing.
A typical seat belt system comprises a retractor upon which seat belt webbing is wound. After exiting the retractor the seat belt webbing is slidable received upon or over a D-ring which is typically attached to the B-pillar of a vehicle by a fastener. The fastener provides a pivot axis about which the D-ring can rotate. As can be appreciated, as the safety belt webbing passes across the D-ring, it generates friction which requires amongst other things, that the rewind spring of the retractor be strong enough to overcome this friction. Various attempts have been made to provide a D-ring that has the necessary load bearing capacity with features that attempt to reduce the webbing retarding frictional force. U.S. Pat. Nos. 4,389,059 and 4,349,217 are illustrative of D-rings which comprise a roller mechanism for reducing retarding frictional forces. Occasionally, as the D-ring is rotated about the axis of its fastening bolt, the webbing may slide or bunch up within a corner of a slot in the D-ring. As can be appreciated, this bunching makes it more difficult or impossible to retract the webbing as the webbing may become caught in this slot.
It is the object present invention to provide a D-ring characterized by a low frictional retarding force and one that is less susceptible to web bunching while providing greater comfort to the belt wearer.
Accordingly, the invention comprises: a D-ring for a safety belt comprising: a plate member adapted to be mounted relative a cooperating structure. The member includes a top and sidewalls and bottom defining an opening. A roller is supported on a flexible shaft and the shaft is supported in bearings located in the member. The shaft deflects in response to high belt forces permitting the roller to move into contact with a mechanical stop provided by the bottom of the plate. In this manner the shaft and its bearings need not absorb the web load and are designed primarily to significantly reduce belt friction.
Many other objects and purposes of the invention will be clear from the following detailed description of the drawings.